Eddie Cahill (born January 15, 1978) is an American actor known for playing the role of Det. Don Flack on CSI: NY.

Cahill was born in New York City, New York. He is of Irish and Italian descent.

Cahill starred on a short-lived WB drama, Glory Days (2002). His television guest star appearances include Charmed, Felicity, Sex & the City, Dawson's Creek, Haunted, and Law & Order: Special Victims Unit. He also was a recurring guest star in the comedy Friends as Rachel's hot young assistant, Tag Jones. In the movie Miracle (2004), he played hockey goalie Jim Craig.

Eddie Cahill was born in New York on January 15, 1978. With Italian and Irish decent, Eddie is the second born to his parents, having one older and one younger sister. He graduated from Byram Hills High School in Armonk, New York in 1996. He appeared in Nicky Silver's Off-Broadway play The Altruists in 2000. He made his move onto TV screens in June of 2000 guest-starring opposite Sarah Jessica Parker in "Sex and the City." He made his big break in October of 2000 winning the role of Rachel's new assistant in "Friends." His other TV appearances include "Charmed," "Felicity," "Law & Order: Special Victims Unit." In 2001 Eddie signed a holding deal with The WB Network to star in his own TV show. "Glory Days," debuted in 2002 but, while well received by critics and viewers, it did not last long. Not discouraged, Eddie went on to make appearances in the series "Haunted" and "Dawson's Creek." In 2004 he made his leap onto the big screen in Disney's Miracle playing his childhood hero Jim Craig. He continued his movie career in 2005 appearing in the movie Lords of Dogtown. Also, in 2004 he joined the cast of the newest addition to the "CSI" franchise "CSI: New York." He can be seen playing Detective Don Flack every Wednesday on CBS at 10/9 central.